Blindstitch sewing-machine.



1. WH ITELAW.

flBLlNDSTlTCH SEWING MACHINE.

APPLlCATlbN FILED MAY13.1915- Patented Dec. 10, 1918.

4 SHEETS4-SHEET 1;

J. WHITELAW.

BLINDSTITCH SEWING MACHINE.

' 4 APPLICATION FILED MAY 13 1915. 1,287,157.

Patented Dec, 10

' 4 SHEETS-SHEET 2.

I. WHITELAW. BLINDSTITCH SEWING MACHINE.

APPLICATION FILED MAYl3i I9l5. 4 1,287,157., I Patented Dec.10, 1918.

4 SHEETS-SHEET 3.

- iillllbtfllllli in J. WHITELAW.

BLINDSTITCH SEWING MACHINE.

APPLICATION FILED MAY 13. l9l5.

1,287,157. Patented Dec.10, 1918.

4 SHEETS-SHEET 4.

JAMES WHITELAW, OF ST.'LOUIS, MISSOURI.

' BLINZDSTITCH SEWING-MACHINE.

To all 'uihom it may concern: Be it known that I, JAMES WHITELAW, a

' citizen of the United States, residing at $t. Louis, in the city of St. Louis, State of MB- souri','have inv'e1..ed certain new and useful Improvements in 'Blindstitch'- Sewing-Machines, of which the following is a specification. a

. My invention relates to improvements in blind stitch sewing machines, and] in some partieulars more especially to a but'ton holefinishing machine for use in shoe-factories and the like. p

Among the objects .of my invention are to provide a work handling mechanism for a button-hole-finisher in vwhich the work may be handled in such fashion that the stitched side of the work is uppermost, so that the operations may be best controlled by the operator; to provide a feed construction capable of high speed operation and able to handle fine leather, at high speed,

, without injuring the finished. leather-surface; to provide a construction that "willcompact the threads against or mto thestitched side of the leather. in the course of the stitching operation; to provldeimproved plu'ngebmechanism adjustable freadlly, and

while the machine is running, and generally and in detail to improvetheconstruction and functioning of. the work handling structure of machines of the class described.

In the drawings wherein I have illustrated an embodiment of my invention- Figure 1 is a side elevation with. parts broken away, showing some of the basecontained parts.

Fig. 2 is an enlargeddeta-il of parts of the feeding mechanism, in association with .the plunger and needle.

frame parts of the machine.

Fig. 3 is a cross section through the work handling end ofthe machine'on line of Fig. 1', showing the plunger and heater .mechanism, in association with the presses foot and clamp-plate. Fig. 4 is a plan view of the base-carr ed parts of the mechanism, taken on line 4.-4 of-Fig. 3.

Fig. .5 is a top plan view of a presser foot structure, detached, schematically-indicating Fig. 6 is a bottom plan view of the presser foot.

Fig. 7 is a. sectional elevation showing shaft connections. at the right end of the Fig. 11 is a detail of the feed-adjusting structure. 1 i

Fig. 12is a fragment of the work.. I

. In the drawings 20- indicates the machine base-casting, 21 the post, 22 the arm, and 23 the head. -The stitch-forming mechanism herein shown, that is carried "by-head 23, I

need not describe in detail, as it is fully de 1 scribed and is claimed in myeopending ap plication Serial No. 81Z,579ffiled-.February 9th, 1914. It suflices here to point out that the stitch formingmechanism that I illustrate,.and prefer to'employ, makesa seam ofthe lock stitch variety, with-its plane of *1) STATES PATENT OFFICE.

Specification of Letters Patent. Patentd Dec 10 1918. -App1ic ation filed m s, 1915. Se1'ia lNo.:27,78 9.

needle reciprocation acutely inclined to the seam-length or direction "of feed, and with the needle thread overcast across the surface ofthe work to form bights or loops each springing from the points of entrance.. 1. of two successive stitchesinto the work and each. having its bend or crest partly encompassing the oint of emergence of the la st made one 0 said stitches from the work. The head 23 carries at its lower extremity adjacent to the base 20, an upper presser foot 25 preferably' rigid and stationary, and

that has a suitable opening, as hereafter more fully described, through which the needle hasaccess to thework so that the thefront A needle may enter and emerge from face or stitched side'of the work.

The needle n cooperates with the rotary hook I1. and the needle thread is acted upon by a two-part looper Z-that serves to manipulate the needle thread for the formation of mechanism is an organized apparatus car-' ried by the head andarranged to be driven cyclicly through a maingear 9 that meshes with agear 26 on the main shaft 27 ofthe I machine. This main shaft preferably ex-. .tends longitudinally through the arm 22,

and its power receiving end is provided with pulley 28 and, preferably, with stop-motion clutch mechanism generally indicated as SM, that is operable automaticallyto stop the shaft always in substantially a predetermined position of rotation when the clutch controlling lever is appropriately shifted. This stop mechanism per 86 forms no part of my present invention, but a suitable stop motion structure, like that suggestively illustrated in the present drawings, is fully v shown and described in my Patent N 0. 1,191,635, dated July 18th, 1916.

In the intended operation of this machine Y the work,which may .be a button-hole fly driven from the-main shaft.

F for shoes, with a thrum 'T connecting the 'smallvends of the button-holes as. yet loose on the inner or flesh side of the leather, (see Fig. 12)is positioned under the rigid presser foot 25 and fed therebeneath in a direction away from the eye of the observer in Fig. 1; and the work is lifted in nodes to be penetrated by the needle between successive feed operations,"so that the needle may enter and emergefrom the stitched side, or flesh "side, of the work, p'assin from one side thereof to t e other in a plane at an acute'angle to the line of thrum, and

below the thrum has made in its underside a dove tail groove 30 extending fore-and-aft or directly away from the observer in Fig. 1, at, say, a 28 angle to the plane of needle-reciprocation and in this groove is slidingly' mounted the feed dog or bar 31. This bar is in the' Jform of a flat serrated strip that extends inrear of the presser foot and is then bent up to make a cylinder end for sliding or slot connection. 32 with the operating lever 33. This lever. extends up in a suitable recess in the head frame 23 to which it is pivoted as at 34 and its upper end is pivoted as at 35'to the link 36,that has its other end pivotally connected to an adjustable wrist-pin structure 37 operativelyrconnected with the end of the main shaft 27 In the specific construction shown the gear 26 on the end of the main shaft 27 bears a fixed stud 38 that has a Tshaped slot 39 in which is slidable, for radial adjustment, the head of a bolt 40."' The bolt is surrounded by a sleeve 41- that may be clampedby the nut.

V 42 against the stud-face to retain the wristpin structure thus formed inany desired position of radial adjustment. The end of link 36 surrounds this sleeve 41, andlmant festly by radial adjustment of wrist-pin, the

length of throw of the lever 33 may be adjusted, to alter the stitch-length. Of course as the main shaft rotates the lever 33 is vibrated, slidingthe feed dog 31 foreandaft through the slip-connection 32, and if the work be pressed against the feed bar 31 during the forward movement of the latter the work will, of course, be fed forward.

For cooperation with the feed dog, this having only a two-way motion, I provide a complemental feed member that I term the walking-foot, having positive up and down motion to bring it into or out of operative correlation with the feed dog, and preferably capable 'of following the forward or feeding motion of the dog 31. Y In the construction shown, 45 indicates the walking foot arranged directly below the feed-dog 31, to work against the latter, the walking foot being pivoted to a vertical link 46 that in turn is pivoted to the horizontal arm of a bell crank lever 47, the vertical arm of which is connected by link 48 with a crank 49 mounted on a rock shaft 50. When shaft 50 is oscillated, obviously the walking foot is bodily raised and lowered and its positively-effected movement is supplemented by incidental movements occasionedprimarily by the feed dog 31. A spring 51 connected between the lower extremity of the walking foot and the pin '52 on link 46 tends to hold the walking foot always with its upper surface substantially horizontal, and a spring 53,

connected between the rear portion of the walking foot and the pin- 54 on the frame, tends always to hold the foot in its forwardmost position. The oscillations of the rock shaft 50 being properly timed, the walking foot-45 rises to press firmly against the under side of the work when the feed is ready to advance, and is firmly pressed against the work during the feeding movement. The arrangement of the walking foot on the vertical link 46 pivoted atboth ends,

enables the walking foot to cooperate'with the feed-dog during the entire forward movement of the latter,and when, after the forward movement is completed, the rock shaft causes the walking foot to descend to inoperative position, its'springs 51 and 53 restore it to its normal position with respect to the link 46.

In order to clamp the work against the under side of the presser foot during the intervals when the feed is not in action, I

employ a lower spring-pressed ,presser-foot or clamp plate 56 extending fore-and-aft beneath the stationary presser foot. This plate is carried by a',,vertical guide post 57 guided in the subjacent machine base 20, and it is related to the walking foot 45 in such fashion as when the latter is exerting its forcible pressure upon the under side of the work in opposition to the feed, the clamp Figs. 1 and 3, is seated at its bottom in a slide block 58 sliding vertically in a recess 59 inthe frame, and the pivot pin 47' for the bell crank lever 47 of the walking foot mechanism is connected to this block, whichis normally sustained in raised position by 'a strong leaf spring 60. Such spring 60 extends along the under side of the base 20 to a supporting bracket 61, where the springfulcrums between its ends on a brace 62 and is adjustable as to tension by means of the bolt 63 that may raise or lower its fastened end, beyond the fulcrum.

Now it will be apparent that as the walking foot is forced upward into contact with the feed, by an extent of motion of rockshaft 50 in excess ofthat which would just produce such contact, .the walking foot itself becomes-the fixed point or fulcrum of a the lever-system and the pivot pin 47 of the bell crank lever 47 forces downward the slide block 58 against tension of spring 60,

so carrying-down the pressure-plate 56.

A suitable rigidpresser foot, 25, may beconstructed as shown in Figs. 5 and 6 to provide in its under surface a recess 70 for the goods to which the needle may have access through a slot 71 alining with the path of needle reciprocation, and therefore at an acute angle,to the line of feed. In its upper surface, in the particular construction shown, the presser foot may vhave inlaid therein a needle-guiding, hardened steel plate, 72, and it may be provided with a looper receiving. recess 73 in which are made points. Beyond the recess 7 0 the underside of the presser foot is made flat, as .at-74, to form an anvil-surface for the beater, (to be described) to work against.

3 J I preferalso that on the urfder surface of the presser foot a thrum gatherer 75 be provided, such thrum gatherer, in the specific construction shown, being a shallow inverted trough, with its channel tapering toward the rear, disposed at'its axisapproxima'tely parallel to the line of feed, such' trough being inserted in a suitable recess in v the under side of the presser foot', preferably with its edges slightly projecting below the plane of the under-side'of said presser foot. The narrow throat of such gathering channel opens to the goods recess very near to the portion of slot 71 where the needle cooperates with the work. A

For cooperation with such thrum gatherer I preferably provide on the clamp plate 56 a nressure spring 76, that. is shown as a dou-- bled leaf-spring extending outin-front of the presser foot and back over the top of the plate 56, the extremity of saidsprmg being shaped to conform with the edges of the thrum gatherer and being arranged for depression into a shallow recess 77 in the plate 56.

It will be apparent now that as the work i is' fed forwardpthrums are gathered into line and fed forward precisely to the stitching point in a compact bundle, through the action of the thrum gatherer, that isaidedf' by the action of the spring 76 which holds' 1 the work very {closely up to the thrum gatherer, even when the plate 56 is depressed, soas to minimize the chance of any loose thread escaping the action of such gatheren Below the needle slot 71 opening to the work-recess 70 of the presser foot therev works a\plunger or bender 80, this beingpreferably a vertically guided member extending through the subjacent frame arm the clamp plate 56, and lnto the presser-foot recess 70. The plunger, when raised, spans I the needle slot 71 and the portions "7 0 of the presser foot flanking the needle channel 71" prevent the plunger from lifting the work.

too high, so that they thus act front guides, by which the location of the work with respect to the needle path'is determined from the front or stitched faceof the goods a seam-beater 85, in the form of a flat ended rod, working through an appropriate open- 1.

ing 86 in thevclamp-plate 56 against the slight ridges on; the unbroken fai r-" side of the work, that maybe raised by the presence of the blind-stitchesfin'therleather.

The plunger and; b'e'a'te'r, are both-Q mounted, adjustably f-ifi desired, on a hea'. 88, that is arranged. to be vertically recip cated by means of a fcamand roller struc ture, whereof tl.'re,"c'anr 1 is driven by a.'rock and the depth of penetration of the needle into the work is made uniform. 1

Supplementing the plunger 1 provide flat under surface or'anvil 74 of the presser I foot, this beater being preferably mounted uniform and attractive finish onthestitched side of the work, as wellas flattening any} shaft that rm yfarm the plunger shaft; I

and the limits. of} throwlof suchhead 88 -I; U

preferably make tobeyariableg-hy adjust ment at the will of the operator., The ad-fi justment devices provided are such'that thef operator may change the adjustmente'ven i.

while the machine is running and; the ad- Q,

justing finger-piece is front of the base 20.

positioned on the loo -45 3 It willbe observed with-respect to Fig. 9 that, as'plu'nger shaft 92 is lowered by the rocking of the gate on which it is carried, the

V The roller Q9Lonhead S 'en'gageS adouble'.

wall cam slot 90'in thefcam 91, such slot 'affordinga dwell, a rise and'a second dwell. Shaft '92 that {bears the cam 91 extends lengthwise of lthe machine beneath the base thereof', and is mounted for bodily movement to vary the limits of the throw of the 1 plunger that isdue to theaction of the cam. Thus shaft '92 is mountedfin a gate, com-"- the latter being pivoted as at 96 -96 in the prising two end pieces 93 and 94 and the, longitudinal. connecting post orgate-axis 95,

frame-end on the one hand and in bearing wall 97 on the other hand, so that shaft 92 stands normally below and in rear; of the post 95. The end arm;93 has a lever extension 98 with which 'coiiperates an adjusting bolt 99, taking "through a slot in'lever. 98and opposed by a tension spring 100, the head 101 of the bolt extending forward 7 through the front wall of the base for convenient manipulation to oscillate the gate,

1 thereby to raise or lower: the plunger shaft shaft receiving bearing-therein), and both said shaftsare connected with the main shaft 27 ,to receive motion therefrom. I In the specific construction shown,- the mam shaft, within post 21, bears. a single eccen tr c 105 which communicates its motion I .Ihrough a link 106' to a lever 107 that is con- 4o nected (as best shown in Fig. 7) with the extremity of shaft 50, and that also has I 'jpivotal connection, at a suitable distance from said shaft 59 as a center, with a link 108 that is connected by crank 109 with the plunger shaft 92.

.t'inie? of the cam may remain substantially shaft 92 downward'around shaft 96 at its unchanged. LQf course, the swinging of center tends to. move.'the cam.bodily to the right as it descends, so tending to retard the time when the cam 91 willraise the plunger;

this assuming that theshaft '92 were to receive no rotary displacementincidentally to its bodlly movement in the gate. But, as

'1 may be noticed in. consideration of Fig.9, th1s bodilyjdlsplacement of shaft 92 (throwing it downward andwto the right in Fig.

9) results in a rotative'displacement of shaft 92, counter-clockwise" Fig. 9, thereby advancing the cam rotatively and so tending to ma ntain the cam-time substantially uni- I 1. Ina blind stitch sewing combination of a frame providing apresser form with respect to the operationof the main shaft.

In order. that the clamp plate 56 and;

walking foot 45In'1'ay be lowered readily to permit of insertion of the-work, a lever 110 may be pivoted at 111 as shown in Fig. 2'

for operation by a knee-lift link 112 to depress the spring 60v that normally, holds up the stated partsfito their work. This lever may also be caused to work the clutch shifter, for the stop motion device SM but as its connections for this purpose are=of present application I no importance to the have omitted the same.

While I have herein described in some detail a particular embodiment of my invention for purposes of full disclosure it will be apparent to-thos'e skilled in the art that many changes might be made in details of construction and arrangement withoutdeparture from the spirit and scope of my invention and within the scope of the appended claims.

Having described my invention, what I claim is: machine, the

foot having an' opening to permit cooperation of the needlev with .the work,-stitch forming means above said presser foot ineluding a reciprocating needle, 'plunger i neans below said presser foot to elevate the work into stitch-receiving relation to the needle, and work-feedingmechanism comprising a feed member arranged on the same side of the work as the presserfoot and having only a fore-and-aft movement, a. walkingfoot below the work andmeans to give said walking foot an up and down movement only, said Walking foot beingflfree to follow the advancing movement of the feed when elevated by its moving means.

2.In' a' blind stitch sewingma chine the combination of a frame, a presser foot, carried thereby having an opening to give the needle access to the work therebelow, stitch forming mechanism above said presser foot including a reciprocating needle, plunger mechanism below said presser foot for elevating nodes of the work to the action of the needle, and feeding mechanism comprising a sliding feed-member mounted in the under side-of the presser foot, means to reciprocate said feed-member, a walking foot on the same side of the work as the plunger, means to raise and lower said walking foot, said walking foot being free with respect to said means to follow the advancing movement of the. feed while the walking foot is raised, and means normally to clamp the work against the under side of the presser foot, associated with said walking foot to be depressed when ,the'walking foot is positively V raised.

j .maintain" substantially-uniform the time of 3. In a blind stitch sewing machine, the combination of a frame providing an over. hanging arm, a head, stitch formingmecha:

7 work handling mechanism comprising in w combination a plunger, a plunger operating nism carried by'said head, apresser foot below sa1d stitch forming mechanism, .a sliding feed member mounted in the under side of said presser foot, a shaft for driving said stitch-.forming'mechanism mounted in said arm and having a crank, and means 'for con nect ng sa1d sliding feed-member with said shaft comprising a lever having connection with sa1d feed-member and having connection with'a crank on said shaft.-

4. In a'blind stitch sewing machine, the

combination of a frame providing an over-' hanging arm, a head, stitch forming mechanism carried by said head, a presser foot belowsaid stitch forming mechanism, a sliding feed member mountedin the underside of said presser foot, ashaft-for driving said stitch-forming mechanism mounted in said arm-and having a crank, and means for-connecting said sliding feed member with said shaft comprising a-lever connected with said 2 5 feed. and a wrist pincarried by said shaft and adjustable radially with respect thereto,

said wrist, pin having connection with-said lever.

' 5., In a machine of the-character described the combination of a Presser-foot, a; plunger therebelow, a rock shaft for operating saidplunger,-and meansfor -bodily moving said plunger. I a 6.111 a machine of the. character described rock shaft to vary the; limits of throw of the the combination 'ofa frame, a presser foot, a

- I plunger below said presser foot, means for vertically reciprocating said plunger including a rock shaft, means for bodily adjusting means carrying Said marshes-far bodily displacement, a plunger 'operat vely. assoc1--* said rock shaft to vary the limits of throwofthe plunger, said means'including an adjusting membenextending to the front of the frameifor operation exterigrly to the frame; 7.'In a blind StitchseWing machine the combination of work-handling means 'i'nclud Y ing a; plunger, .mean's. to recrproc'ate' sa1d plunger including ar/rock shaft, means for bodily moving said rock shaft to vary the limits of throw of the plunger, and means to vary the limits of throw of the rock shaft to plunge-1. at 1 ijf 1-e11t adjustments-- ofs. In amass j'eigenstates-assets the combination 'of a main shaft, 1a pl er operating rock sh'aft', pivotally '-ad usta le ated with said. rock shaft-for 'variatron of its limit of throw in accordance i with the 'p'osition of the rock shaft, and means connectlng a said rock shajtjwith'the mam shaft operable to vary the limit-of throw of the 'rock shaft to maintain substantially if m time the plunger, under different bodily positions ofthe rockshaft.

9, In a machine of thecharacter described rocksh'aft, a cam carried by said rock shaft associatedwith'the plunger, means supporting saidrock shaft for bodily pivotal displacement, means accessible from the exteriorof. the machinefor adjusting the last said means, tobodily displace the rock shaft for'varying the limits of throw of the plun-' ger, a main shaft, driving connections be tween said main. shaft and the. rock shaft,

operableto vary the limitsfof throw. of the 'rockshaft under different bodily adjustments of the rockshaft, to tend to maintain constant the time of the plunger.

10. In amacliine ofthe character described, a base, a presser foot, a plunger, a

work feeding part, shafts for said plunger and for said work feeding part in said'base, ajpivoted gateilsupporting said plunger shaft for-bodily dis lacement -to vary the of throw of t e plunger, and means i for operating said two shafts, alever fast on said shaftl'forthe work feeding part, a

crank on "the plunger shaft, a link between said lever .and crank accommodating the bodily'movements of the plunger shaft, andmeans to vibrate said lever.

11. In a-buttomhole finislili' machine, a

plunger, a 'presser-foot having .a work re ceiving recess in its underside, and aneedleopening communicating with the recess, and

Y opening communicating with the'rece'ss, and

athrum gatherer comprising a tapering channel, opening to said recess and a channel formed in a trough inserted in a recess in I the Presser-foot, with its converging edges projecting below the plane of said' presserfoot. r

13. In a machine of the character deplate opposed to the presser foot, means to move saidclamp plate, and a spring structure carried by the clamp plate opposing thethrum' cha'nnel.3' I

I 14. In amachine of thelcharacter dev. scribed, means for presenting. the work inbent-position, stitch forming-means includ-" ing a needle disposed to enterand emerge Y from the same side of such bent-work, and

means for beating the pre-formed stitches.

' 1 15. Ina blindi'stitch sewing machine, the combination of work handling means varranged to present the work inbent position and to feed the work,,stitch' forming means arranged to form blind stitches entering and emerging from the' same side of the bent work, and seam-beating means arranged in rear of the bending means with respect to.

the direction of feed. 7

16. In-- a machineo'f the character described, the combination of a presseIf foot,-

blind-stitch forming means above the same,

arranged to work through the presser foot to "entcr'and emerge from the upper surface 7 of the work, a beater below-the presser foot arranged to strike the work below the preformed stitches, and means to operate said beater.

17. In a machine of the character de-' scribed, the combination of a presser foot having an opening, stitch forming mecha:

nism on one side of said presser foot, a

-. plunger on the other side of said presser foot, a beater-in rear of said plunger in the direction of feed, and means to operate the heater and plunger.

18 In a machine of the character 'de scribed, the combination of a presser foot having an opening, stitch forming me'cha-' nism on one side of said presser foot, a plunger on the other side of said presser foot,- a beater in rear of said plunger in the direction'of feed, and adjustable means to reciprocate the plunger and. beater in unison.

19. Work presenting mechanism for sewing machines comprising reciprocable actuating said cam shaft.

In testimony whereof I hereunto set my hand in the presence of two subscribing bender having a cam-engaging member, a cam and cam shaft, and means for adjust-- ably supporting thesameand means for 

